diff --git a/.github/workflows/agent-team-apply-verify.yml b/.github/workflows/agent-team-apply-verify.yml
index 62995ba..c1b25dc 100644
--- a/.github/workflows/agent-team-apply-verify.yml
+++ b/.github/workflows/agent-team-apply-verify.yml
@@ -1286,16 +1286,17 @@ jobs:
           # smuggle newlines/control chars/over-long content into the PR metadata.
           title="$fallback_title"
           if [ -n "$PR_TITLE" ]; then
-            # Reject any control char (incl. newline/tab/NUL/DEL) or > 70 chars.
-            # POSIX [[:cntrl:]] under LC_ALL=C (no GNU-only `grep -P`): matches
-            # 0x00-0x1f + 0x7f. C1 (0x80-0x9f) is already stripped box-side by
-            # sanitize_pr_title; this is the defense-in-depth re-check (§4.6).
-            if printf '%s' "$PR_TITLE" | LC_ALL=C grep -q '[[:cntrl:]]'; then
-              echo "::warning::pr_title rejected (control chars); using fallback"
-            elif [ "$(printf '%s' "$PR_TITLE" | wc -m)" -gt 70 ]; then
-              echo "::warning::pr_title rejected (too long); using fallback"
-            else
+            # Re-validate the box-supplied title as defense-in-depth (§4.6),
+            # BYTE-FOR-BYTE identical to agent_team.dispatcher.sanitize_pr_title's
+            # acceptance test: reject any C0/C1 control char or DEL
+            # ([\x00-\x1f\x7f-\x9f] — note this DOES cover C1, which a POSIX
+            # [[:cntrl:]] grep misses) and cap at 70 *characters* (not bytes, so a
+            # multibyte title is not spuriously rejected). python3 is present on
+            # the runner; an undecodable/invalid title exits non-zero -> fallback.
+            if printf '%s' "$PR_TITLE" | python3 -c 'import sys, re; t = sys.stdin.read(); sys.exit(0 if t and not re.search(r"[\x00-\x1f\x7f-\x9f]", t) and len(t) <= 70 else 1)'; then
               title="$PR_TITLE"
+            else
+              echo "::warning::pr_title rejected (control chars or >70 chars); using fallback"
             fi
           fi
           # The provenance (task id, diff hash, head) lives in the BODY so the